Shyster's thread of Spaaaace.

Postby **tifosi77** » Tue Nov 15, 2022 6:49 pm

For the same reason it's not 12 or 93.

Postby **Shyster** » Tue Nov 15, 2022 8:36 pm

Dunno. IIRC, it was 31 seconds for the Shuttle, so whatever the SLS is doing in that time, it takes two more seconds.

So far, the countdown has been proceeding nominally. The SLS core stage is currently fully fueled and in "topping off" mode, and the second stage is on the process of being filled with liquid oxygen and hydrogen. Fueling is actually ahead of schedule, and it looks like NASA has fixed the leaky connectors that hindered earlier wet-dress rehearsals. Weather looks good, and the range is currently green.

Postby **Shyster** » Tue Nov 15, 2022 10:04 pm

Problem:

An intermittent leak in a hydrogen replenish valve has caused a Stop Flow condition. NASA is sending a specially trained "Red Team" to the pad to see if the leak can be fixed. The valve in question is in the base of the launch pad and not on the tower.

Postby **Shyster** » Tue Nov 15, 2022 10:30 pm

The Red Team is on site at the pad and is working to torque down the bolts on the leaky valve.

Postby **Shyster** » Tue Nov 15, 2022 11:09 pm

Red Crew is clear of the pad. The bolts were loose. Now getting ready to test the valve.

Postby **Shyster** » Tue Nov 15, 2022 11:43 pm

The range has lost signals for one of its radar sites. That would be a no-go for launch. Range is working on resorting connectivity. It sounds like an ethernet switch pooped the bed and needs to be replaced.

Propellant loading has resumed. The hydrogen lost to boil-off during the stop has been replenished and the core is back in top-off mode.

One of the reasons that it takes a couple days to turn around the SLS after a scrub is that literally thousands of gallons of LOX and LH2 boil off in the lead up to launch, and NASA literally has to truck in many tanks of hydrogen and oxygen to replace those losses before it can try for another launch.

Postby **Shyster** » Wed Nov 16, 2022 12:06 am

The valve has been confirmed to be leak-free, so the Red Team fixed the issue. The only problem being worked is the loss of connectivity for the range radar.

Postby **Shyster** » Wed Nov 16, 2022 12:07 am

Postby **Shyster** » Wed Nov 16, 2022 12:21 am

T-10 minutes and holding. This is a planned hold in the countdown. Launch window opens in ~30 minutes. Still no-go on the radar issue, but that is in work.

Postby **Shyster** » Wed Nov 16, 2022 12:24 am

The launch window lasts for several hours, so there is time to resolve issues.

The network switch has been replaced and testing is underway. The switch is also required for the flight-termination system to work properly, so it is a critical piece of communication hardware.

Postby **Shyster** » Wed Nov 16, 2022 1:05 am

Still in hold and now into the launch window. Both stages are fully fueled and in top-off mode. It looks like the range issue still has not been resolved.

Postby **Shyster** » Wed Nov 16, 2022 1:26 am

Polling for launch is imminent.

Postby **Shyster** » Wed Nov 16, 2022 1:33 am

Go for terminal count.

Postby **Shyster** » Wed Nov 16, 2022 1:38 am

SLS is pressing for flight.

Postby **Shyster** » Wed Nov 16, 2022 1:40 am

FTS is armed. APUs have started.

Postby **Shyster** » Wed Nov 16, 2022 1:42 am

Internal power.

Postby **Shyster** » Wed Nov 16, 2022 1:43 am

GLS is go for auto-sequence start.

Postby **Shyster** » Wed Nov 16, 2022 1:43 am

Liftoff!

Postby **Shyster** » Wed Nov 16, 2022 1:45 am

Max Q.

Postby **Shyster** » Wed Nov 16, 2022 1:45 am

SRB separation.

Postby **Shyster** » Wed Nov 16, 2022 1:47 am

Fairing and launch-abort separation.

Postby **Shyster** » Wed Nov 16, 2022 1:51 am

MECO.

Postby **Shyster** » Wed Nov 16, 2022 1:53 am

Postby **DigitalGypsy66** » Wed Nov 16, 2022 7:57 am

Postby **tifosi77** » Wed Nov 16, 2022 10:41 am

Yay, spaceflight! Fun to watch a moonshot; the future is an exciting time.